1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member and to a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member.
2. Description of the Related Art
Various charge-generating substances used for electrophotographic photosensitive members have been developed. Among these substances, phthalocyanine pigments, which have high sensitivity, are often used.
However, higher sensitivity of an electrophotographic photosensitive member is liable to cause photomemory in the electrophotographic photosensitive member by light penetrated from the outside of a process cartridge or an electrophotographic apparatus. Recently, this has been required to be improved. The term “photomemory” indicates a phenomenon in which carriers are accumulated in a portion irradiated with light (irradiated portion) to cause a potential difference between the irradiated portion and a portion that is not irradiated with light, which can cause a reduction in image quality (image reproducibility).
Japanese Patent Laid-Open Nos. 2006-72304 and 2008-15532 disclose a technique in which a phthalocyanine pigment and an organic electron acceptor compound are used in combination, and a technique in which a charge-generating layer includes a pigment sensitizing dopant having an electron acceptor molecule.
However, the use of the techniques disclosed in Japanese Patent Laid-Open Nos. 2006-72304 and 2008-15532 does not result in sufficient improvement in photomemory.